Genes and Genomes Chromosome—A string like, gene-

containing molecule in the nucleus of a cell

Gene—The fundamental unit of biological inheritance

Genome—An organism’s entire complement of DNA

Gene Therapy The manipulation of someone’s genetic

material to prevent or treat disease

An attempt to alter the workings of cells by:• replacing a missing or defective gene with a

normal one • repairing a faulty gene so it will function

properly• activating or deactivating a gene (switching it

on or off)

Two Types of Gene Therapy Somatic cell therapy involves altering genes in

a person’s somatic (body) cells, such as liver or muscle cells, to treat an existing disorder. The alterations can help the person suffering from the disease but are not inheritable—they cannot be passed on to the person’s offspring.

Germ-line cell therapy entails modifying genes in germ-line cells (egg and sperm cells) and zygotes—and these alterations are inheritable.

Gene Therapy Somatic cell therapy—The prevailing

view: if steps are taken to minimize harm, and if the potential benefits are substantial, somatic cell therapy is morally permissible.

Germ-line cell therapy—Safety concerns are so worrisome that, at least in its current immature stage, it is generally thought to be morally unacceptable.

Moral Issues in Gene Therapy

Medical risks and benefits of the therapy

Duties to use the procedures to prevent suffering

Reproductive freedom The morality of practicing positive

genetics

Reproductive Cloning Cloning is the asexual production of a

genetically identical entity from an existing one.

Reproductive cloning is the creation of a genetic duplicate of an adult animal or human; aimed at the live birth of an individual.

Therapeutic, or research, cloning is cloning for purposes other than producing a live individual.

Human Reproductive Cloning Arguments for Cloning:

• Appeal to reproductive liberty• Benefits to infertile couples

Arguments Against Cloning:• Cloning is unnatural.• It violates the right of the resulting clone to

a unique identity or future. • It will result in the demeaning artificial

manufacture of children as products.

The Beneficence Argument for Genetic Enhancement

There is no morally significant distinction between genetic repair and enhancement.

If we have the power to make someone’s life better through genetic enhancement, we should do it.

The Open-Future Argument Against Cloning

Søren Holm: What is wrong with living your life as a

clone in the shadow of the life of the original? It diminishes the clone’s possibility of living a life that is in a full sense of that word his or her life. The clone is forced to [try] to perform a complicated partial re-enactment of the life of somebody else (the original).

The Open-Future Argument Against Cloning

National Bioethics Advisory Commission: [A]ll of these concerns are not only quite

speculative, but are directly related to certain specific cultural values. Someone created through [cloning] may or may not believe that their future is relatively constrained. Indeed, they may believe the opposite. In addition, quite normal parenting usually involves many constraints on a child’s behavior that children may resent.